This invention relates to connectors for attaching detachable electrical power cords to eIectrically powered equipment, especially to personal computers and desk-top laser printers, specifically to an improved connector that locks in place and can be detached from an electrically powered apparatus only by an authorized person. The advantage of the present invention will be realized when same is used in conjunction with other apparatus intended to prevent the use of electrically powered equipment by unauthorized users. Such other apparatus could, for instance, consist of a controlled-access means for simultaneously retaining the electrical plug of the power cord, which is connected to the invention, in a socket in said apparatus while selectively enabling and disabling the flow of electrical current thereto as desired by an authorized user. Alternatively, the power cord to which the present invention (a connector) is attached could incorporate a key-controlled means for selectively enabling and disabling the flow of electrical current through said power cord as desired by an authorized user. Thus, it will be seen that the present invention is simply a power-cord connector that can not be removed from an appliance by an unauthorized person, and that the advantage thereof will be realized only when the power cord attached to the subject connector is provided with an effective, access-controlled means for enabling and preventing the the flow of electrical current through said power cord and connector as desired by an authorized user.
Various devices have been proposed and implemented for preventing the unauthorized use of electrically powered equipment by preventing the flow of electric current through the appliance power cord. Some of these devices are lockouts that enclose the conventional power plug of the appliance cord in such a fashion that the plug can not be engaged in an electrical wall outlet. Other of these devices lock the conventional appliance cord plug into the device, provide a means for supplying electrical power to the device, and further provide a means (usually a key-controlled switch) for permitting or preventing the flow of electricity from the device to the appliance power cord. Still other of these devices utilize a specially designed cord plug that looks into a mating specially designed power outlet to control the availability of electrical current to the power cord.
The number of embodiments proposed and implemented of such locking devices suggests a wide-spread desire to control operative access to various electrically powered appliances and apparatus. The reasons given for wanting to control such operative access are numerous. Among them are: to protect children and other individuals who do not possess sufficient knowledge or understanding of the operation of certain types of electrically powered equipment to operate same safely; to protect delicate electronic equipment from damage by untrained operators; to prevent economic waste of electricity and supplies (as for copy machines, fax machines, and laser printers), and to prevent unnecessary equipment wear; to control the viewing of television and video-tape programming by children; and to preserve the confidentiality of computer files.
Heretofore, however, locking devices such as those recited above were rendered ineffective (sometimes at the complete oblivion of the equipment owner) in the case of an appliance or apparatus equipped with a detachable power cord (such as are most personal computers and desk-top laser printers, for example). In such an installation, an unauthorized user could simply disengage the appliance cord from the appliance or apparatus, engage thereunto an alien, unencumbered power cord, engage the power plug of the alien appliance cord into an electrical wall outlet, and use the appliance or apparatus at will.
Many users of electrically powered apparatus that is equipped with detachable power cords would therefore find it desirable to have a power cord which they could readily engage and disengage from the apparatus, but which an unauthorized person could not disengage. Upon obtaining such a cord, the user could then avail himself of, and effectively use, any desired lockout or other device for controlling the flow of electrical current through the power cord to the user's electrically powered apparatus.